High resolution interferometer with multiple-pass optical configuration

Abstract

An interferometer having resolution fourteen times higher than a conventional single-pass interferometer has been developed by creating multiple-pass optical path. To embody the multiple-pass optical configuration, a two-dimensional corner cube array block was designed, where its symmetric structure minimized the measurement error. The effect from the alignment error and the imperfection of corner cube is calculated and is in picometer level. An experiment proves that the proposed interferometer has optical resolution of approximate 45 nm and its nonlinearity is about 0.5 nm in peak-to-valley value. (C) 2009 Optical Society of America